Method of making a vessel for molten metal

Abstract

A holding furnace for molten metal comprises an inner vessel formed of flat, rigid, heat-resistant panels. The panels are held in sealing engagement with one another at abutting edge surfaces by the action of inwardly directed pressure applied to the panels by an integrally cast refractory outer vessel through the intermediary of a resilient layer of heat-resistant fibrous material. The pressure is applied as a result of the shrinking that the casting compound undergoes during the setting. When the inner vessel is being made, the panels, to which the resilient layer has initially been applied, are held together by the action of a reduced pressure in the inner vessel as the latter is positioned in a furnace casing interiorly lined with a mineral wool insulation. The inner vessel then is cast around with a refractory casting compound for forming the outer vessel.

I claim as my invention: 
     
       1. A method of making a vessel for molten metal, said vessel comprising a box-like inner vessel having bottom and side walls formed of rigid heat-resistant panels which are sealingly joined together along confronting edge surfaces at the inside corners defined by the bottom and side walls, and an insulation covering the outer sides of the bottom and side-wall panels of the inner vessel, said method comprising the steps of applying to the outer sides of said panels a resilient layer of heat-resistant fibrous material,   placing said panels in their proper final positions relative to one another substantially without securing them together,   generating a reduced pressure in the inner vessel to cause the panels to be clamped together by the pressure of the surrounding atmosphere,   while maintaining said reduced pressure placing the inner vessel with said resilient layer in a casing interiorly lined with a heat insulation with the bottom and all side walls of the inner vessel spaced from said insulation,   filling the spacing between the heat insulation of said casing and the resilient layer of said bottom and side walls of said inner vessel with a refractory casting compound, and   causing said casting compound to set and shrink and thereby clamping together the panels of said inner vessel.